Foams and, in particular, foam emulsions are complex dispersion systems which do not form under all circumstances. Slight shifts in foam emulsion composition, such as by the addition of active ingredients, may destabilize the foam.
There have been a few attempts to create foams containing lanolin.
U.S. Pat. No. 5,679,324 pertains to an aerosol foamable fragrance composition, translucent in its pre-dispensed state, which forms a fast-breaking foam. The composition contains a surfactant selected from the group consisting of ethoxylated lanolin oil derivatives, propoxylated lanolin oil derivatives, and mixtures thereof, a propellant, a fragrance, a thickener, and a cosmetic vehicle (preferably water). Emollients may be included, however, being translucent, the composition cannot comprise significant oil concentrations (which would make it opaque). Apparently the foam breaks spontaneously upon discharging from an aerosol container (with no need of any rubbing or sheer force application), thus making it impractical for certain applications such as intravaginal applications.